Description of the change

Change the field names of Transform to be a, b, c, d, e and f, instead of m11, m12, m21, m22, m31 and m32.

Closes #72

Checklist:

• Added the change to the changelog's "Unreleased" section with a reference to this PR (e.g. "- Made a change (#0000)")
• Linked any existing issues or proposals that this pull request should close
• Updated or added relevant documentation
• Added a test for the contribution (if applicable) (Project has no tests)